1. Field of the Invention
The present invention relates to an audio/video (A/V) device, and more particularly, to a system and method for sharing information of contents possessed by A/V devices having network interface, which are connected with each other on a network, and efficiently controlling the execution of the contents.
2. Description of the Related Art
With the rapid development of technology of processing digital A/V, diverse A/V devices such as digital televisions (TVs), set-top boxes, digital versatile disc (DVD) players, and digital amplifiers have been installed and used at home and offices. Users at home or offices can conveniently control these A/V devices using remote control units. However, as the number of A/V devices installed in a predetermined space increases, controlling the A/V devices becomes more complicated and difficult.
Therefore, approaches for systemizing a plurality of A/V devices by associating them with one another and enabling a user to conveniently control the systemized A/V devices have been studied. Here, the A/V devices are connected with each other through network interface, thereby forming a single A/V network system.
As one of the approaches, an expandable Home Theater (XHT), i.e., a middleware for A/V home networking has been developed and proposed. The XHT is a home network solution based on a digital TV that has been developed by Samsung and has been adopted for the U.S. Consumer Electronics Association (CEA) standard.
According to the XHT, an A/V device connected with a digital TV and a plurality of digital TVs can be controlled using an Institute of Electrical and Electronics Engineers (IEEE) 1394 cable that can stably transmit high definition (HD) signals and an Internet protocol (IP) that is a communication protocol usually used on the Internet. When the XHT is used, a user in a bedroom can view digital broadcasting using a digital broadcast receiving function of a digital TV installed in a living room.
A cheap network interface unit (NIU) using the XHT is made in a format of a memory card and is thus easy to change according to a receiving scheme such as a terrestrial, satellite, or cable scheme, thereby reducing the financial burden on a broadcasting company. In particular, the XHT can provide diverse portal services through a browser embedded in a digital TV.
In a sequence of operations of A/V devices implemented using the XHT, a local IP address is automatically allocated to each of A/V devices on an XHT network according to a predetermined address allocation algorithm. Next, each of the A/V devices having the local IP address expresses its own device information in an eXtensible Markup Language (XML) file, i.e., a deviceInfo.xml file, according to a predefined syntax form (defined by a deviceInfo.xsd file) and transmits the XML file to the other A/V devices. The deviceInfo.xml file includes a uniform resource identifier (URI) of an XHT931.xsd file describing a set of HyperText Transfer Protocol (HTTP) commands for operating the A/V devices.
The A/V device generating the deviceInfo.xml file generates the XHT931.xml file including the HTTP commands, which the A/V device supports, with reference to the XHT931.xsd file.
The deviceInfo.xml file expressing the information of the A/V device and the XHT931.xml file including the HTTP commands supported by the A/V device are received by any one of the other A/V devices, which can recognize the information of the A/V device transmitting the files based on the received files and can control the A/V device using the HTTP commands.
FIG. 1 shows an example of the content of a deviceInfo.xml file 10 generated by an A/V device according to the syntax of a deviceInfo.xsd file. The position information, date, and version of the deviceInfo.xsd are written at a deviceInfo tag position 12. The name of a manufacturing company, URI, and manufacturing date of the A/V device are written at a manufacturer tag position 13. The functional name, subname, and model name of the A/V device are written at a functionType tag position 14. A coding method and a bitrate for streaming are written at a 1394StreamSource tag position 15.
Information regarding user interface is written at a userinterface tag position 16 and information regarding user interface notifying the occurrence of an event is written at an eventNotificationUI tag position 17. Referring to FIG. 1, a user interface function is not supported. The name of an XHT standard supporting HTTP commands and a file (i.e., an XHT931.xsd file) defining the HTTP commands are written at an HTTPCommandInterfaceRef tag position 18.
FIG. 2 shows an example of the content of an XHT931.xml file 20 generated by an A/V device according to the syntax of an XHT931.xsd file.
The URI, date, and version of the XHT931.xsd file that is referred to are written at an OperationList tag position 22. Therebelow, operations codes supported by the A/V device are written. Referring to FIG. 2, the A/V device supports a function 23, i.e., EVENT-NOTIFICATION that notifies other A/V devices of the change of a state of the A/V device, a function 24, i.e., POWER that turns on or off the power of the A/V device, a function 25, i.e., PLAY that initiates playback of content, a function 26, i.e., STOP that stops the playback of content, a function 27, i.e., PAUSE that temporarily holds the playback of content, and a function 28, i.e., REWIND that rewinds content.
When a first A/V device receiving the deviceInfo.xml file and the XHT931.xml file controls a second A/V device transmitting the two xml files, the first A/V device can control the second A/V device using an HTTP command combining a URI and an operation code.
For example, when the first A/V device is a digital TV and the second A/V device is a source device storing a transport stream (TS), it is assumed that a user inputs a command for viewing a program included in the TS into the digital TV using a remote control unit. If an IP address allocated to the source device is 192.168.0.2, the digital TV just transmits an HTTP command “http://192.168.0.2/CEA931?play&press” to the source device. Since an A/V device complying with the XHT standard has a web server and includes a device controller converting the HTTP command into an operation therewithin, the source device can execute an operation corresponding to the transmitted HTTP command. Accordingly, the source device transmits the TS to the digital TV using an IEEE1394 network and the digital TV receives and decodes the TS and displays the decoded TS to the user.
As described above, the XHT facilitates communication and control between a plurality of A/V devices so that a user just controls only one A/V device to effectively control the other A/V devices. However, taking account of the popularity of a large capacity hard disc and users' diverse tastes for multimedia contents like video, still images, and audio, the conventional XHT standard is not very satisfactory for using and managing diverse contents on an A/V network.
Therefore, a technique of efficiently arranging and displaying contents on an A/V network to a user and enabling the user to conveniently enjoy a desired content is desired.